Platen leveling



H. M. PURCELL PLATEN LEVELING Oct. 18, 1949.

4 Shets-Sheet 1 Filed July 8, 1947 VIIIIII mvzu'ron HOWAXD M. 'PURe'JELLATTORNEYS Oct.

Filed July 8, 1947 H. M. PURCELL PLATEN LEVELING 4 SheetsSheet 2ATTORNEYS Oct. 18, 1.949. PURCELL 2,484,908

PLATEN LEVELING Filed July 8, 1947 4 Sheets-Sheet 3 ATTORN i Y8 Oct. 18,1949.

H. M. PURCELL $484,908

PLATEN LBvELme Filed July 8, 1947 4 Sheets-Sheet 4 INVENTOR Y HOWARD M.PURCELL ATTORNEYS Patented on. 18, 1949' PLATEN LEVELING Howard M.Purcell, Philadelphia, Pa asslgnor to H-P-M Development Corporation,Wilmington, Del., a. corporation of Delaware Application July 8, 1947,Serial No. 759,668

15 Claims. (Cl. 60-97) This invention relates to presses, andparticularly to multi-point presses wherein there are a plurality ofpoints at which power is applied to the press platen for moving it.

The particular object of the present invention is to provide an improvedarrangement for maintaining a multi-point press platen level.

Still another object of this invention is to provide a means formaintaining the platen of a multi-point press level and which utilizes aminimum of auxiliary equipment in accomplishing this result.

Still another object of this invention is the provision of a mechanismfor maintaining a multi-point press platen level which is substantiallyinstantaneous in operation.

Still another object is to provide a means for maintaining a pressplaten level which may readily be installed on the platen of any press.

It is also an object of this invention to provide in combination with ahydraulic press having a plurality of spaced rams acting on a platen, ameans for controlling the delivery of fluid to the said rams whereby thesaid platen remains level at all times.

These and other objects and advantages will become more apparent uponreference to the following description taken in connection with theaccompanying drawings in which:

Figure l is a diagrammatic view of a twopoint hydraulic press having aplaten leveling mechanism according to this invention:

Figure 2 is a fragmentary view as showing a somewhat modifiedconstruction to be utilized in connection with the arrangement of Fi ure1;

Figure 3 is a view similar to Figure l but showing a somewhat differentarrangement wherein separate pumps are employed for supplying fluid tothe platen actuating rams:

Figure 4 is a detailed view showing one part of the pump control linkageof Figure 3;

Figure 5 is a diagram of the electrical control circuit for thearrangement of Figure 3;

Figure 6 is a view showing still another form of this invention andwherein the control of the platen is accomplished through pressure;

Figure '7 is a perspective view showing how this invention can beapplied to a press having four rams connected with the platen;

Figure 8 is a diagrammatic view showing this invention applied to a longplaten having a plurality of rams spaced therealong; and

Figure 9 is a perspective view showing a simplified form of thisinvention.

General arrangement According to this invention the platen of a presshaving a plurality of actuating means for the platen is maintained levelby means of a flexible member such as a cable which is connected betweenthe press head and press bed and which passes across the press platen.The flexible member is anchored on one of the head or bed and there arepulleys or other journaling means on the platen and the other of saidhead or bed whereby tilting movement of the platen will produce relativemovement between the flexible member and the one of said head or bed onwhich it is journaled. This relative movement may be resisted by heavyyielding means which normally support the weight of the platen or may beemployed for actuating hydraulic or electrical means which control thedelivery to the actuating means for the press platen to set up forcestherein which will restore the platen to its level condition.

Preferably, the actuating means for the press platen are hydraulicmotors such as rams and the means for maintaining the platen level, andwhich are under the control of the flexible member, comprise fiowdividing valves, pressure control valves, or delivery control means forpumps supplying the said rams.

Structural arrangement Referring to the drawings, the press shown inFigure 1 comprises a bed It and a head i2 which is connected with thesaid bed by the strain rods it. A platen it is slidable on strain rodsit between the head i2 and bed it. The platen is actuated by a pair oframs it which extend into the cylinder 253 which are preferably integralwith the head 15?.

A pump 22 is connected by a conduit 2d with the retracting means of therams i8 and, by a conduit is with the inlet of a flow dividing valve 28.The flow dividing valve 28 has twoservice ports which are connected bythe conduits at with the advancing means of the rams iii. The valve 28also has therein a valve member 32 which in its center position offersequal restriction to the fluid fiow from the conduit 26 to each of theconduits 3t. Upon movements in either direction the valve member 32decreases the restriction to flow to one of the conduits 3t whileincreasing the restriction to flow to the other conduit 3t.

For pre-fllling the advancing means for the rams during their initialdownward movement,

ace-secs and for exhausting the said advancing means during theretracting movement of the rams, there are preferably provided surgevalves 84 which connect the said advancing means with the reservoir 36in response to suction in the ad-- vrncing means or in response to apredetermined pressure acting in the retracting means of the rams. Acheck valve 38 opens from the reservoir 38 into the conduit 25 forsupplying makeup fluid to the pump 22 during the working stroke of therams 88.

Control of the pump delivery is had by a linkage to which includes thevertical rod t2 that passes through an arm H on the platen it and has asits upper end a solenoid armature arrangement as. Energization of thesolenoid Ml will lift the rod 52 and through the linkage QB place thepump 22 in position to deliver into the conduit 26. De-energizing of thesolenoid dd permits the springs :16 to move the rod 32 downwardly and toplace the pump in position to deliver to the conduit 25.

For actuating the valve member 32 of the flow dividing valve 28 thereare provided a pair of flexible cables indicated at 68 and 50. The endsof these cables are anchored as at 52 and 5 8 to the bed I and passupwardly therefrom to the pulleys 58 and 53 on the platen I5. The cablesthen pass across the platen in opposite directions to the pulleys 60 and82. Then the cables extend upwardly and over the pulleys M and 66carried by the press head. The ends of the cables are then fastenedtogether by a suitable fitting 8B. The anchors at 52 and d arepreferably adjusted to hold the cable perfectly taut throughout itslength.

The valve member 32 of the valve 28 is connected by the lever which ispivoted at 72 with the member 68. A pin and slot arrangement at Minterconnects the lever and member for simultaneous movements.

It will be apparent that, should the right end of the platen i6 tiltdownwardly as viewed in Figure 1, the length of cable from the anchor 52over the pulley 56, pulley 60, and extending upwardly to pulley 68, willbecome greater than the length of the cable extending from the anchor55, the pulley 5B, pulley 62 and up to pulley 68. Accordingly, therewill be a movement toward the right of the horizontal reach of the cableextending between the pulleys 64 and 66 and also a movement to the rightof the member 68 and the lower end of the lever 10. This brings about amovement to the left of the upper end of the member Ill and of the valvemember 32 which operates to restrict the flow of fluid from the conduit26 to the right hand conduit 30, and to reduce the restriction to flowfrom the conduit 26 to the left hand conduit 30. The pressure acting onthe right hand ram I8 is therefore less than that acting on the lefthand ram I8 and unbalanced forces are generated thereby which tend torestore the platen I6 to its level condition.

It will be apparent that either direction of tilting of the platen I6from level will be fol lowed by the setting up of unbalanced forcesthereon tending to bring it back to its level condition.

The ends ofthe cables 48 and 50 may be adjusted at their anchors 52 and54 respectively in order to pre-set the valve 28 to bring the rams I8into synchronism under normal operating conditions.

In certain instances wherein the press platen is not of too great aweight, it may be maintained level by mechanical means prior to the timeit engages the work. This may be done by making the flexible cablesumciently strong to support the weight of the platen and making thejournals or pulleys on the platen in the head of sufficient size andstrength also to support the weight of the platen. The connection of thecable to the flow dividing valve is then made as is shown in Figure 2.In this flgure there is a block it which is securedto the cable ends andwhich carries a pin I8 extending into the bifurcated lower end of thelever I0. Rigidly mounted on the press head are a pair of stop membersor abutments es of the same width as the block it and bearing againsteither side of the blocks are the plates t2 which are apertured topermit the passage therethrough of the cable member.

Spaced from the plates 82 are the blocks 8% which are rigidly secured tothe press head as by the screws as and between which and the blocks 82there bear the heavy compression sprin s 88.

It willbe apparent that the arrangement is that of a self-centeringdevice and that the block it will normally be retained in its Figure 2posi= tion and that movement thereof in' either direction will beresisted by the full thrust of one of the springs 88. As mentionedbefore, this arrangement will operate to maintain the platen level upuntil the time it strikes the work, provided the cable and pulleystherefrom and the springs 88 are made sufliciently strong.

There is shown in Figure 3 a somewhat modifled arrangement wherein eachof the two rams for actuating the platen has its own individual pump.

The construction of the two rams and the actuating circuits therefor areidentical and accordingly a description of only one thereof will begiven and the one on the other side of the press will be correspondinglynumbered with the addition of an A.

Referring to Figure 3, the actuating rams are indicated at 90 and 90A.Connected between the advancing and retracting means of the ram 90 is apump 92 having a servomotor mechanism 94 shiitable for selectivelyreversing the pump delivery. A linkage 96 is connected to the servomotor94 with a rod 98 which is arranged like the rod 62 in Figure 1 with anactuating solenoid I00. A link I02 is included in the linkage 96 and isoperable, when extended, to move the pump 92 toward retraction strokeposition. Thus, if the pump 92 is delivering to the advancing means ofthe ram 90 and the link I02 is extended, the delivery of the pump 92will be reduced and the ram 90 will.

slow down.

The link I02 is best seen at Figure 4 wherein it comprises a casing I04having therein a movable member I06 normally urged in one direction by aspring I08 and adapted for being moved in the other direction byenergization of a solenoid 0. One end of the casing I04 is connectedwith the linkage 96 and the opposite end of the member I05 is alsoconnected with the said linkage. It will be apparent that energizationof the coil I08 will operate to increase the effective length of thelink I02.

A simplified electrical control circuit for the arrangement of Figure 3is shown in Figure 5. In this figure there are the power lines LI and L2and therebetween there is connected a contactor coil A in series withthe normally opened start button H2 and the normally closed stop buttonIII. The start button H2 is toy-passed by the normally opened blades A-Iof the contactor coil A which provides a holding coil for the contactorcoil after the latter has been energized by closing the push button II2.

Connected in parallel with coil A are the solenoids I and I00-Aenergizable for shifting their associated pumps 92 and 92--A intoforward delivery position.

The coil IIO of the extensible link I02 is connected between the linesL--I and L2 and in series with a normally opened limit switch LS-I whilethe coil I I0A of the extensible link I02A is connected in series withthe normally opened limit switch 1.8-2.

The limit switches are positioned as shown in Figure 3 on either side ofa member II 3 which is secured to the cable H5. As explained inconnection with Figure 1 tilting movements of the platen IIS will beaccompanied by movement in one direction or the other of the member I I3with the cable I I5. For example, tilting of the platen IIS downwardlyat its right end will result in a movement toward the left of the memberI I3 and closure of the limit switch LS-2. This will reduce the deliveryof the pump 92-A and thereby slow down the rate of movement of the ram90A. This will operate to restore the platen to its level conditionwhereupon the limit switch LS2 will again open and full delivery of thepump 02-A will be resumed.

In Figure 6 there is shown an arrangement somewhat similar to that shownin Figures 1 and 3 and wherein each of two rams has its own source ofpressure fluid. but wherein the control of the tilting of the platen isaccomplished by pressure responsive means.

Referring to only the left hand side of the arrangement shown in Figure6, and'applying the same numerals to the right hand side with theaddition of an A, there is a ram I20 which has its advancing andretracting means connected with the service ports of a reversing valve I22. The valve I22 receives pressure fluid from a conduit I26 which leadsto one port of a valve i526 which also has another port thereinconnected by the conduit I28 to receive pressure fluid from the pumpI38. The valve 526 has therein a valve member i 32 which is normallyurged by the spring ltd into position to provide free communicationbetween the conduits I20 and E28. Movement of the valve member H32 inthe opposite direction will set up a restriction to flow between thesaid conduits.

The valve member 832 has thereon a fluid operable area connected by theconduit I36 with the conduit I25 and acting in a direction opposite tothe thrust of the spring H30. The conduit i2 5 is also connected by aconduit I323 with the smaller side of a piston I d0 which is'connectedwith the movable flow control member of the pump I 30 and acting in adirection to increase the deliver of the said pump. The pump is alsourged toward increased delivery position by a spring I452 and theopposite side of the piston I 40 is also connected by a conduit I'M withthe conduit E28 for urging the pump toward decreased delivery position.

The spring Ififl has its end opposite the valve member I32 engaged by acup washer which is abutted by the end of a r0 I06 adjustably carried ina fitting I50. The fitting I 56 is connected for actuation by lever I52which is pivoted at I54 and which has its lower end connected with thecable I50 for movements therey.

ISO-A through the valves I 26 and I2B-A with the said advancing meanswill obtain until the platen tilts from a level position. Upon anydelivering movement of the platen I58 the lever I52 will be shiftedabout its pivot I54 to increase the tension on one of the springs ofthe,

valves I20 and I26A and to decrease the tension on the other. Assumingthat the platen has delivered downwardly on its right side as viewed inFigure 6, the tension on the spring I34 will be increased and that ofthe spring I 34-A will be decreased. This will cause the valve member I32--A to yield under a lower pressure and thus to set up a restrictionto flow from the conduit I 28-A to the conduit I24A. On the other hand,the valve member I32 will only yield at a higher pressure and thereforeless restricted communication is had between the conduits I25 and I24.Normally, the valves I26 and I2t--A will be adjusted whereby the valvemembers Hi2 and I32--A will fioat in a semirestricting position and anytilting of the platen will be accompanied by an immediate increase inpressure on the lagging ram and a decrease in pressure on the leadingram.

In Figure 7, there is shown arrangement whereb a press platen havingfour actuating rams could be controlled according to this invention.

In Figure '7 a first cable 200 is connected to pass diagonally across orthrough the platen 202 and is connected with the control means 20% forthe rams 205 positioned at the said diagonally opposite corners. Therams 208 on the other diagonally opposite corners are similarlycontrolled by a cable 2! 0 which crosses the platen diagonally and inalignment with the said rams. By the arrangement shown in Figure 7 theplaten is maintained substantially level because each corner of theplaten is controlled by the one diagonally opposite; Thus, the platencannot tilt in any direction without disturbing the balance of thecontrol system for the several rams.

In Figure 8 there is shown an arrangement wherein there are a pluralityof rams arranged in a line to actuate a platen such as a bending brake,a shear, or the like. In accordance with the principles set forth inconnection with Figure 7, the two rams 282 are connected togetherthrough a flow dividing valve 25 which is controlled by the cable Zitwhich passes across or through the platen Zit between the rams 292.Similarly, the two rams 220 are connected .together by the flow dividingvalve 222 which is controlled by a cable 22% arranged relative to theram 220 like the cable 266 is relative to the ram 2 i2.

As in the case of the arrangement shown in Figure 7 the platen 2th ismaintained level at all times and tilting or bending in any directionwill result in immediately setting up restoring forces thereon.

Figure 9 shows a simplified arrangement wherein there is a single cable300 which is anchored at 302 on the bed 304 and which-extends upwardlyand around the pulleys 306 and 308 on the platen 3I0. From the pulley303 the cable 300 passes upwardly and around the pulley 3K2 on the presshead 3M. The end of the cable which is actuated by the lever 320 which.is

pivoted onthe head 3 and connected with the cable 300.

The arrangement shown in Figure 9 is quite simple and is adequate in anyinstance wherein it is not desired to support the platen weight by thecable, or wherein it is not desired to provide for a pre-stressed cableas in the other modifications illustrated.

It will be understood that this invention is susceptible to modificationin orderto adapt'it to different usages and conditions and, accordingly,it is desired to comprehend such modifications within'this invention asmay fall within the scope of the appended claims.

I claim:

1. In a press having a press head, a press bed, and a press platenreciprocable therebetwecn; a plurality of fluid operable means forreciprocating said platen; a fluid source for supplying pressure fluidto said means; flow controlling means for determining the relativeamounts of fluid supplied to said means; a substantially inextensibleand flexible member connected between said head and bed and extendingtransversely across said platen; and means connecting said member withsaid flow controlling means for operation thereof by deflections of saidplaten from a level position.

2. In a hydraulic press; end members constituting a press head and apress bed, and a press platenv reciprocable therebetween; a plurality offluid operable means for reciprocating said platen; means of supplyingactuating fluid to said fluid operable means; flow controlling meansoperable for determining the relative quantities of fluid supplied tosaid fluid operable means; and means for actuat ng said flow controllingmeans in response to tilting movements of said platen comprising aflexible and substantially inextensible member anchored on one of saidend members. extending therefrom to said platen, across said platen andthence to the other of said end members; and means connecting the end ofsaid flexible member at said other end member to said flow controllingmeans.

.3. In a press; end parts constituting a head and a bed, and a platenreciprocable therebetween; a plurality of fluid operable motor meansconnected with said platen for driving it in its reciprocatingmovements; a flexible cable extending transversely across said platenand from one end thereof toward one of said end parts and from the otherend thereof toward the other of saidend parts; means anchoring one endof said cable on one of said end parts; the other end of said cablebeing movable relative to the other end part; a fluid source forsupplying fluid to said fluid operable means, flow dividing meansbetween said source and said fluid operable means to determine thedivision of fluid therebetween; and means connecting the said other endof said flexible member with said flow dividing means.

4. In a hydraulic press having a head, a bed, and a platen reciprocabletherebetween; a plurality of spaced fluid operable motors for drivingsaid platen in its reciprocating movements; means for. supplyingactuating fluid to said motors; flow controlling means for determiningthe relative amounts of fluid to be supplied to said motors; and meansof actuating said flow contil trolling means in response to tiltingmovements of said platen comprising cable means anchored on said bed,extending to said platen, transversely across said platen, and thence tosaid head to be connected with said flow controlling means.

5. In combination with a press comprising rigidly interconnected endparts and a platen reciprocable therebetween, and having a plurality offluid operable motors for actuating said platen; fluid flow controllingmeans for determining the supply of fluid to said motors and operable tovary the relative quantities supplied to the separate motors; and meansof actuating said flow controlling means comprising cable meansconnected therewith, extending transversely across one of said endparts, then to opposite ends of said platen, then across said platen inopposite directions, and then to the other oi said end parts and rigidlyanchored thereon.

6. In a press having a head, a bed and a platen; cable means having itsopposite ends anchored on said bed and extending therefrom to saidplaten, then across said platen in opposite directions, then to saidhead, and then across said head; means normally urging said cable towarda predetermined fixed position whereby said platen is normallymaintained level; fluid motors acting on said platen at spaced points;control means for regulating the fluid supply to said m0- tors; andmeans responsive to movements of said cable relative to said headbrought about by the tilting of sa d platen for actuating said controlmeans to regulate the fluid supply to said motors to set up unbalancedforces on said platen tending to restore the same to a level position.

7. In a press having a spaced apart head and bed and a platenreciprocable therebetween: cable means having its opposite ends anchoredon said bed and extending therefrom to said platen in a directionparallel to the movement of said platen, across said platen in oppositedirections, then to said head also in a direction parallel with themovement of said platen, and then across said head; centering springs onsaid head engaging said cable and normally urging it into apredetermined condition for normally maintaining said platen level;motor means acting on said platen at spaced points; control means forcontrolling the energization of said motor means; and means responsiveto relative movements of said cable and head as brought about by tiltingmovements of said platen for actuating said control means to vary theenergization of said motor means to set up unbalanced forces on saidplaten tending to return it to a level position.

8. In a press having a head and a bed spaced apart vertically and aplaten reciprocable therebetween; cable means anchored at opposite endsof said bed and extending vertically therefrom to said platen, thenacross said platen in opposite directions, then vertically to said head,and then across said head; centering spring mean continuously urgingsaid cable into a predetermined position relative to said head; andfluid operable means responsive to relative movement between said headand cable for setting up unbalanced forces on said platen.

9. In a press having end members constituting a head and a bed and apress platen movable between said end members; a plurality of fluidoperable motors connected with said platen for reciprocating the same; apump connected with each said motor for supplying actuating fluidthereto; delivery controlling means for each of said pumps operable forvarying the delivery thereof; and means for operating said deliverycontrol means to vary the delivery of said pumps to said motors formaintaining said platen parallel to a predetermined plane at all timesand comprising cable means extending transversely across said platen andthen to said end members in a direction parallel with the direction ofmovement of said platen; means anchoring said cable means on one of saidend members; and means connecting said cable means remote from the pointof anchoring thereof with said delivery controlling means.

10. In a hydraulic press; a head, a bed and a platen; a plurality offluid motors connected for actuating said platen; cable means anchoredat opposite ends of said bed and extending therefrom to said platen in adirection parallel with the direction of movement of said platen;journal means at opposite ends of said platen, said cable means passingover said journal means, transversely across said platen, and towardsaid head in the same said direction; journal means at opposite sides ofsaid head, said cable means passing over said journal means andextending transversely across said head; and means connected foroperation by said cable means in response to movements thereof relativeto said head for determining the relative quantities of fluid to besupplied to said motors.

11. In a hydraulic press; a press head, a press bed, and a press platenreciprocable between said head and bed; spaced fluid operable motors foractuating said platen; pressure fluid supply means for supplyingactuating fluid to said motors; flow controlling means operable todetermine the relative quantities of fluid to be supplied to saidmotors; yielding means continuously urging said flow controlling meanstoward one extreme position; and cable means also connected with saidflow controlling means for the operation thereof upon deflections ofsaid platen from a level position, said cable means extending therefromto said platen; then across said platen t the opposite end thereof, andthen to said bed to be anchored thereon.

12. In a press having end parts constituting a head and a bed, a platenreciprocable therebetween, a plurality of spaced fluid motors foractuating said platen, and fluid supply means for supplying actuatingfluid to said motors; platen leveling means comprising flexibleinextensible means extending from one side Of one of said end parts tothe other side of the other of said end parts and passing transverselyacross said platen; journal means at oppoiste sides of said platen forsupporting said flexible means; means rigidly anchoring said flexiblemeans on one of said end parts; and means responsive to relativemovements between said flexible meansaand the other of said end partsfor varying the relative amounts of fluid supply from said supplyingmeans to said motors for urging said platen 'in a direction tocounteract said relative movement.

13. In a press having a head, a bed, a platen reciprocable therebetween,a plurality of spaced fluid motors for actuating said platen, and fluidpressure supply means to: mp y s actuating fluid to said motors; meansfor maintaining said platen parallel to a predetermined reference planethroughout its reciprocating movements and comprising flexibleinextensible means extending from each side of said head to the oppositesides of said bed and passing transversely across said platen; journalmeans at opposite sides of said platen for supporting said flexiblemeans; means rigidly anchoring said flexible means at each side of saidbed; journal means at each side of said head, said flexible meanspassing thereover and across said head and being interconnected; springmeans urging said flexible meansinto a predetermined position relativeto said head and being sufficiently strong to maintain said platen levelbefore it engages the work; and other means responsive to movements ofsaid flexible means relative to said head for varying the relativequantities of fluid supply to said motor means for maintaining saidplaten level under load.

14. In a press with a head, a bed, a platen reciprocable therebetween, aplurality of spaced fluid motors for actuating said platen, and fluidpressure supply means for supplying fluid to said motors; meanscomprising flexible inextensible means connected between said head andbed, extending transversely across said platen, and operating as aparallel motion mechanism; said flexible means extending across saidhead and being connected and being anchored on said bed; and meansresponsive to relative movements between said flexible member and headbrought about by tilting movements of said platen for varying therelative pressures at which fluid is supplied to said motors.

15. In a press having a head, a bed, a platen,

a plurality of actuating motors for said platen, and fluid supply meansfor said motors; leveling means for said platen comprising flexibleinextensible means extending from said head to said bed, passingtransversely across said platen, and acting as a parallel motionmechanism; said flexible means extending across said head and beingconnected; adjustable anchor means rigidly securing said means to saidbed; valve means connected between each of said motors and said fluidsupply means and operable to control the pressure supplied to saidmotors; and means responsive to movements of said flexible means acrosssaid head as brought about by tilting movements of said platen foroperating said valve means to vary the pressures acting on said motors.

HOWARD M. PURCELL.

Name Date Coyle Apr. 26, 1910 Monier June 6, 1944 FOREIGN PATENTSCountry Date Germany Oct. 15, 1929 Number Number

